There's been a bunch of keys posted on eBay recently.
Contact the sellers, to see if they happen to have yours.
The broken tip can be removed from your lock by spraying some WD 40 in the slot and turning the tumbler to the lock position with a pair of fine needle nose pliers.
The broken tip can be pulled out with some effort in the locked position.
Take the tip and the AN number to a locksmith, and a new key can be made if an original cannot be found.